#include <cstdio>
#define N 1010
using namespace std;

int n, tot, ans;
bool f[N][N];
int a[101];

int main() {
	freopen("testdata.in", "r", stdin);
	freopen("testdata.out", "w", stdout);
	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) {
		scanf("%d", &a[i]);
		tot += a[i];
	}
	f[0][0] = true;
	for (int i = 1; i <= n; ++i) {
		for (int j = tot / 2; ~j; --j) {
			for (int k = tot/2; ~k; --k) {
				if ((j >= a[i] && f[j - a[i]][k]) || (k >= a[i] && f[j][k - a[i]])) {
					f[j][k] = true;
				}
			}
		}
	}
	for (int i = tot / 2; i; --i) {
		if (f[i][i]) {
			ans = i;
			break;
		}
	}
	if (ans == 0) {
		printf("Impossible");
	} else {
		printf("%d", ans);
	}
	fclose(stdin);
	fclose(stdout);
	return 0;
}